1. Field of The Invention
The present invention relates to power transformers and more particularly to an encapsulated transformer construction which exhibits high electromagnetic efficiency.
2. Brief Description of The Prior Art
Power transformers are widely used for voltage conversion. Transformers include primary and secondary windings which are physically separated from each other. The windings are coupled electromagnetically through a ferromagnetic core.
Various construction techniques have been adopted to meet the mechanical and electrical requirements of various transformer designs.
For example, the prior art teaches:
The use of a unitary bobbin having three flanges which permits the winding of both primary and secondary coils on the same bobbin. The aperture of the bobbin fits over the middle leg of an E-core transformer windings.
The use of injection molding encapsulation for paper wound fly back transformers and the like is taught by U.S. Pat. No. 3,626,051.
The encapsulation of current transformers is known from Martincic U.S. Pat. No. 4,199,743.
Each of these prior art inventions addresses the numerous problems which must be overcome to encapsulate a transformer assembly. However, in the prior art encapsulation of power type transformers has not performed. It is known that power transformers are not perfectly efficient and that resistive losses in the windings result in the generation of heat in the transformer assembly. Other sources of heat include core losses which result in heating of the core material. It has been conventional to expose as much of the windings as practical to the air as an aid in the dissipation of this heat.